Unity WallpaperSwitcher is a new tool which lets you have a different wallpaper for each Unity workspace (viewport).

You can already set different wallpapers for each workspace in Ubuntu (Unity) by using the Compiz Wallpaper plugin but this has one major drawback: the desktop icons are hidden. However, that's not the case with Unity WallpaperSwitcher: you can set a different wallpaper for each workspace and the desktop icons will continue to be displayed, as you can see in this short demo video:

The app, developed by Jacob Vlijm (who also released Unity LauncherSwitcher recently, a tool which changes the Unity Launcher pinned apps depending on the current workspace), is very easy to use: simply start Unity WallpaperSwitcher, enable it, set a wallpaper for each workspace and that's it:

Unity WallpaperSwitcher remembers each of your workspace-specific wallpapers and changes it each time you switch to a different workspace. When you disable the app, all workspaces are set to the currently used wallpaper however, the wallpapers set for each workspace will be remembered and they will be used the next time you enable it.

Because Unity WallpaperSwitcher doesn't directly set all the wallpapers and instead it changes it as you switch between workspaces, the Unity Workspace Switcher won't display different wallpapers for each workspace. Unfortunately there's no way around this due to the way the app works (and it works like this to allow having icons on the desktop, so it's a pretty good trade-off I’d say).